Centrifugal pump.



No. 7l7,096. Patented Dec. 30, I902.

E. G. HARRIS.

CENTRIFUGAL PUMP.

{App cat on fled Oct 19 1901 2 Sheets-Sheet I.

(No Model.)

WW ATTORNEYS No. 70,096. Patented Dec. 30, I902.

E. G. HARRIS.

GENTBIFUGAL PUMP.

(Application filed Oct. 19 1901 (N0 MudeL; 2 Sheets-Sheet 2.

INVENTOR xl momns Nitn STATES ELMO G. HARRIS, OF ROLLA, MISSOURI.

CENTRIF UGAL PUMP.

SPECIFICATION forming part of Letters Patent No. 717,096, dated December30, 1902.

Application filed October 19,1901. Serial No. 79,194. (No model.)

To all whom it may concern:

Be it known that LELMO G.HARR1S,a citizen of the United States ofAmerica,and a resident of Rolla, in the county of Phelps and State ofMissouri, have invented certain new and useful Improvements inCentrifugal Pumps, of which the following is a specification, referencebeing had to the accompanying drawings, forming a part thereof.

Myinvention relates to improvements in centrifugal pumps; and itconsists in the novel means employed for removing water from the spaceon the rear or inactive side of the propelling-Wheel and for preventingaccumulation of water therein during the operation of the pump, in thenovel means for compounding the pump, in the novel means employed forpreventing backflow of water through the joint between thepropellingwheel and the casing, and in many other features, ashereinafter pointed ontin the claims.

The objects of my invention are to reduce friction in centrifugal pumps,and particularly friction between the water and the parts of the pump,to prevent in an improved manner accumulation of water on the rear orinactive side of the propelling-wheel, to obtain the advantages ofcompounding in a single structure and without material increase in size,cost, or space occupied, to avoid the use of packed joints orpacking-rings in the joint between the propelling-Wheel and the casing,and generally to improve the efficiency of centrifugal pumps and toobtain increased economy therefrom.

I will now proceed to describe certain forms of centrifugal pumpsembodying my invention and will then point out the novel fea turesthereof in claims.

In the accompanying drawings, Figure 1 is a central vertical section ofone form of centrifugal pump embodying my invention. Fig. 2 is a detailview of the propelling-wheel looking from the bottom upward. Fig. 3 is adetail view illustrating the arrangement of the guide-blades in thedischarge throat. Fig. 4 is a view similar to Fig. 1 of a compound pumpsimilar in other respects to the pump shown in Fig. 1, and Fig.6 is adetail View illustrating the arrangement of the guide-blades of thecompound pump.

Referring first to the form of pump shown in Fig. 1, the said pump has acasing inclosing the revoluble propelling-wheel 1, which casing isformed in two sections 2 and 3, of which 2 contains the inlet-passage 4and the annular discharge-chamber 5, adapted to be connected to thedischarge-pipe 6. The other section 3 of the casing contains theprincipal portion of the propelling-wheel and has a stuffing-box bearing7, through which passes the driving-shaft 8 of the propelling-wheel.

The propelling-wheel has blades or vanes 9, which extend from the centeror axis of revolution of the wheelto the discharge-openings thereof. Itis not essential that the blades extend to the center of the wheel; butit is preferable that such shall be the case, as the water can be givena steady rotary motion-with fewer blades than when the latter do notextend to the center. of theblades are at right angles to the plane ofrevolution, as shown in Fig. 3. This also is preferable, but notessential. The inner edges of the blades incline forwardly, so as topart the approaching water without causing eddies, as indicated byshading at 10 10, Figs. 1 and 2.

In the pumps shown in Figs. 1 and 4. the joint at 11 11 between thepropelling-wheel and the lower section of the casing is a loose jointand no attempt is made to render it wator-tight by the use ofpacking-rings or the like; but instead the blades 9 of the wheel projectbelow the said joint, and small supplementary blades 12 are provided onthe under side of the wheel, where they will act on water in the spacebetween the wheel and the lower section of the casing. The centrifugaleffect onthe water is the same whether it is passing through the joint11 11 or through the main channels of the wheel between the blades 9,and therefore backflow of water through the joint 11 11 is prevented.The water-friction in the joint 1111 is inconsiderable. I i

An important feature of this invention is the means employed for keepingthe chamber 13 upon the rear or inactive side of the wheel free fromwater during the operation of the pump. For this purposelintroduce intosaid chamber air derived from the water passing The outer tips thechamber 13 at a point near the lower edge of the wheel, where saidchamber is in communication with the discharge-chamber 5 of the wheeland also through a gage-glass 17 with the chamber 13 at a higher point.

The pressure in the chamber 13 is that of the water at the point whereit passes from the wheel into the discharge-chamber 5. At this point thevelocity is high, and therefore the pressure in chamber 13 is less thanthe pressure in the chamber 5 and discharge-passage 6. This is inaccordance with wellknown laws of hydraulics. The air in the dome 15,the pressure in which is that of the water in discharge-pipe 6, iscapable, therefore, of displacing water in the chamber 13, and will doso when the valve 16 is opened.

The gage-glass 17, is employed to indicate what water,if any, is withinthe chamber 13. A pressure-gage 18 may be provided to show what pressureexists in chamber 13. Its use is not'necessary; but the information itgives is desirable.

In another application for Letters Patent, filed August 17, 1900, SerialNo. 27,167, I have described a centrifugal pump wherein water within thechamber on the rear or inactive side of the wheel is displaced by airadmitted from the outside through a suitable air-cock by reason of thefact that the velocity head of the water on leaving the wheel is greaterthan the head at the discharge-outlet of the pump, against which thepump works, so that suction is produced tending to draw water from thesaid chamber on the rear side of the wheel. In the pump above described,however, it is not essential that the velocity head shall be greaterthan such head against which the pump works, since water in the chamber13 is expelled therefrom not by suction, but by air under pressurederived from the water flowing through the pump. 7

The dome 15 may be located at any convenient point at which air tends tocollect.

The amount of air required is very small, and if the water carriesnaturally any considerable quantity of air or other gas no air-pipe 14is necessary.

I preferably employ guide or deflecting vanes 19, which encounter thewater as it leaves the wheel. These vanes deflect the water downward,thus stoppingits revolution and checking its absolute velocity as soonas it escapes fromthe propelling-vanes, thereby reducing friction loss.In dredge-pumps, however, these guide-vanes should be omitted and thethroat 20, in which they are located, should be shortened.

A centrifugal pump cannot begin to discharge under a head which it iscapable of maintaining after the discharge is started. Therefore to aidin starting the pump I connect to the discharge side of the pump at apoint between the pump and the check-valve in the discharge pipe (if anysuch checkvalve be employed) a waste-valve 21, which may be openedpartly or completely when the pump is first started, thereby temporarilyreducing the head against which the pump works, and as the speed of thewheel and the flow of water increase the valve 21 may be closedgradually until the pump is working against the full head. i

In the operation of this pump water is drawn up through thesupply-passage 4 by reason of the water above being forced out throughcentrifugal force generated by the revolution of the propelling wheel,air being drawn in through the pipe 14 and mixed with the entering waterif the water does not already contain sufficient air or other gas. Thewater so rising has motion imparted to it by the blades of the revolvingpropelling-wheel and passes out through the passage of the wheel intothe throat 2 0 and discharge-chamber 5,and sointo the discharge passageor pipe 6. As the water emerges from the wheel it encounters thedeflecting-bladeslQ and is deflected downward thereby,its rotativemotion being stopped and its absolute velocity checked, and thereforeits pressure increased. The air carried by the water rises to the top ofthe dischargepassage,enterin g the dome 15 and thence pass ing throughthe valve 16 into the chamber 13, displacing any water therein andcausing it to flow into the discharge chamber of the wheel. Excess ofair, if any, in passage 6 passes out with the discharge-water.

The valve 16 may be kept open only at such times as water appears in thegage-glass. At other times the valve 16 may be kept closed, if desired.A small portion of the water rising through the admission-passage 4 willpass out through the joint 11 11, circulation being maintained andbackflow of Water prevented by reason of the projection of the blades 9below the joint 11 in the admission-passage and also by reason of theaction of the auxiliary blades 12. The use of a packed joint between thewheel and casing or of packing-rings in such joint is thereby avoided.

In Fig. 4 I have illustrated apump similar in all respects to that shownin Fig. 1, except that the wheel is provided with two sets of bladesoperating successively upon the water, between which are deflecting-blades which do not revolve with the wheel. The pump is therefore compound.The outer rim of the wheel projects below the joint 11.11 and carriesblades 22 in addition to the usual blades 'added pressure by the blades19.

9, corresponding in all respects to the blades 9 of Fig. 1. Between theblades 9' and 22 are stationary blades 23, preferably curved like theblades 19 of Fig. 1, and below the blades 22 are blades 19,corresponding in all respects to blades 19 of Fig. 1. In the operationof this pump the water after leaving the blades 9 is deflected downwardand has its rotative velocity checked by the blades 23. Next itencounters the revolving vanes 22, and again it has rotary motionimparted to it, the vanes 22 at the same time forcing it down withincreased velocity, because of the angle and curve, and, finally, therotative velocity thus imparted to the water is again checked, and it isdeflected downward with In this way the pump is enabled to operateefficiently against a much greater head than would be possibleotherwise. There may be as many sets of deflecting-vanes and revolvingpropelling-blades as desired, and by increasing the number of such setsthe pump may be compounded to any extent desired with little increase incost or space occupied.

\Vhat I claim is 1. In a pump, the combination with a rotarypropelling-wheel and a casing having inlet and outlet passages andinclosing a chamber between itself and said wheel, of a passageconnecting said chamber with a portion of the outlet-passage in whichair or other gas carried by the water may collect.

2. In a pump, the combination with a rotary propelling-Wheel and acasing having inlet and outlet passages and inclosing a chamber betweenitself and said wheel, of an airdome communicating with theoutlet-passage at a point where air or other gas carried by the watertends to collect, and means connecting said air-dome and chamber.

3. In a pump, the combination with a rotary propelling-wheel and acasing having inlet and outlet passages and inclosing a cham ber betweenitself and said wheel, of a passage connecting said chamber with aportion of the outlet-passage in which air or other gas carried by thewater may collect, and means for introducing air into the enteringwater.

4. In a pump, the combination with a rotary propelling-wheel and acasing having inlet and outlet passages and inclosinga chamber betweenitself and said wheel, of a passage connecting said chamber with aportion of the outlet-passage in which air or other gas carried by thewater may collect, and an air-pipe connected with the inlet-passage.

5. In a pump, the combination with a rotary propelling-wheel and acasing having inlet and outlet passages and inclosing a chamber betweenitself and said, wheel, which chamber communicates, past the edge ofsaid wheel, with the space into which fluid emerging from the wheel isdischarged, of a passage connecting said chamber with a portion of theoutlet-passage in which air or other gas carried by the water maycollect.

(5. In a pump, the combination with a rotary propelling-wheel and acasing having inlet and outlet passages and inclosinga chamber betweenitself and said wheel, of a passage connecting said chamber with aportion of the outlet-passage in which air or other gas carried by thewater may collect, and a gageglass indicating the height of liquid insaid chamber.

7. In a pump, the combination with a rotary propelling-wheel having acentral inlet and annular discharge outlet, and having blades forimparting motion to the fluid, of a casing having inlet and outletpassages, an auxiliary passage connecting said inlet and outlet passagesbeing provided between the wheel and easing, the blades of the wheelprojecting into the inlet-passage, thereby tending to cause fluid topass from the inlet to the outlet, both through the wheel and throughthe passage between the wheel and the casing.

8. Ina pump, the combination with a rotary propelling-wheel having acentral inlet and annular discharge outlet, and having blades forimparting motion to the fluid, of a casing having, on one side of saidwheel, inlet and outlet passages, and auxiliary blades carried by saidwheel and located in the space between the wheel and the casing,thepassages between said auxiliary blades communicating only with the inletand outlet passages of the casing.

9. In a pump, the combination with a rotary propelling-wheel having acentral inlet and annular discharge outlet, and having blades forimparting motion to the fluid, of a casing having, on one side of saidWheel, inlet and outlet passages, the blades of the wheel projectinginto the inlet-passage, and auxiliary blades carried by the wheel andlocated in the space between the wheel and the casing.

10. In a pump, the combination with acasing having inletand outletpassages, of a rotary propelling-wheel within said casing,having intakepropelling-blades arranged to receive the fluid from the inlet-passage,and having also an annular rim substantially longitudin'al with respectto the axis of rotation, and carrying other propelling-blades projectingfrom it, and deflecting-vanes interposed between such successive seriesof propellingblades.

11. In a pump, the combination with a casing having inlet and outletpassages, of a rotary propelling-wheel within said casing arranged todeliver the fluid in substantially the direction of the axis ofrotation, and having intake propelling-blades and a rim projecting insubstantially the direction of the axis of rotation and carrying otherpropellingblades, and deflecting-vanes interposed between suchsuccessive series of propellingblades.

vanes interposed between such successive series of propelling-blades,and located upon 10 the outside of the inlet-passage.

ELMO G. HARRIS.

Witnesses WM. MOOAW, V J. A. SPELMAN.

